REGULATION OF THE IGF-I RECEPTOR GENE BY WT1

描述(改编自申请人的摘要)：总体目标 本研究旨在评估胰岛素样生长因子-IR基因表达在脑出血中的作用。 肾脏正常发育及其在肾脏疾病中的作用 发展如肾母细胞瘤。肾母细胞瘤WT1的产物 抑制基因，是一种锌指转录因子，一般 抑制其目标基因。WT-1的表达是正常肾脏所必需的 WT-1基因座的发展和突变或丢失通常与 肾母细胞瘤。调查人员此前曾提出，WT-1规则 IGF-IR基因的突变是后肾发育的重要因素， 这种控制机制的改变导致了肾脏的异常 发展。调查员现在建议检查涉及的机制 WT-1对IGF-IR表达的调节作用。主要的假设是 将测试WT-1的各种亚型控制IGF-IR基因的表达 通过差异结合和蛋白质-蛋白质相互作用 转录因子。提出了四个具体目标。1)展示 293人胚胎内源性IGF-IR基因表达的调控 内源性WT-1基因表达和/或WT-1对肾细胞的调控 行动。2)评估自然发生的和临床上的影响 WT-1相关突变形式对小鼠胰岛素样生长因子-IR基因表达的调控 缺乏WT-1的肾来源细胞系。3)调查相互作用 WT-1蛋白与转录激活剂Sp-1的结合，这是必需的 对于基本的IGF-IR启动子活性，这可能是一个必要的成分 用于WT-1介导的抑制IGF-IR基因表达。4)识别 其他可能与WT-1相互作用并参与其活性的蛋白质； 这些可能包括修改WT-1的其他转录因子或蛋白质 结构。

DESCRIPTION (Adapted from the applicant's abstract): The overall goal of the proposed research is to assess the role of IGF-IR gene expression in normal renal development and its contribution to disorders of kidney development such as Wilms tumor. The product of WT1, the Wilms tumor suppressor gene, is a zinc-finger transcription factor that generally represses its target genes. WT-1 expression is necessary for normal kidney development and mutation or loss of the WT-1 locus is often associated with Wilms tumor. The investigator has proposed previously that WT-1 regulation of the IGF-IR gene is an important factor in metanephrogenic development, and that alterations in this control mechanism result in aberrant kidney development. The investigator now proposes to examine mechanisms involved in regulation of IGF-IR expression by WT-1. The main hypothesis to be tested will be that various isoforms of WT-1 control IGF-IR gene expression through differential binding and protein-protein interactions with other transcription factors. Four Specific Aims are proposed. 1) To demonstrate regulation of endogenous IGF-IR gene expression in 293 human embryonic kidney cells by modulation of endogenous WT-1 gene expression and/or WT-1 action. 2) To assess the effects of naturally occurring and clinically relevant mutant forms of WT-1 on regulation of IGF-IR gene expression in a kidney derived cell line that lacks WT-1. 3) To investigate the interaction of WT-1 proteins with the transcriptional activator Sp-1, which is required for basal IGF-IR promoter activity, and which may be a necessary component for WT-1 mediated repression of IGF-IR gene expression. 4) To identify other proteins that may interact with WT-1 and contribute to its activity; these may include other transcription factors or proteins that modify WT-1 structure.